Photo-toxicity and Essential Oils

I have spent a lot of time considering how to handle an article on this subject- and even more time trying to get out of writing it. The problem is, that while photo-toxicity with some essential oils may be a real problem; I have personally never seen it happen. Not once in all of the years I have been involved with essential oils. At least from a chemistry point of view it has been experienced by some people. I will admit to discounting occasional (exactly once so far) reported experiences where too much time was spent out in the sun or in a tanning bed.  Enough time to create deep burns without the involvement of essential oils.

I am not particularly cautious with my use of essential oils. I do try to use my common sense and to encourage good sense in my family’s use of essential oils. This has been enough to keep myself, my husband, my children and grandchildren safe from photo-toxic experiences.  This is in spite of living and working on a farm, working outside in construction for all of the years that we have been involved in essential oils. Enough said.

Let’s continue with a story to lighten the mood.

There you are, enjoying your breakfast and looking out the window at another beautiful summer day! What should you do? You could spend the day catching up the weeding in the garden. Take your kids to the water park. Or meet your hubby for lunch. Hoping to pull off the latter option, you apply your favorite new essential oil perfume to your throat and wrists with no thought to the possibility of it including photo-toxic essential oils. How you love the aroma of citrus oils, especially lime. So very cheerful, energizing, and uplifting.

Lunch with hubby does not work out and you end up first in the garden. Then, later, at the park. You know how that works. You told the kids that when everybody had weeded two rows you will take them to the water park for the rest of the day. They worked very quickly and you arrived at the park before lunch and stayed all afternoon.

You are so proud of yourself! The garden looks so much better and you have been an amazing mother to your happy and exhausted children. During the evening, however, you notice that the insides of your wrists have a dark pink strip across them that is very sore to the touch. The skin along the side of your neck is beginning to feel tight and itchy. You look in the mirror and, to your horror, you discover dark red stripes with a few small blisters forming. No sunburn anywhere else. Odd. And then it occurs to you-sun and certain essential oils can be a recipe for disaster.

Does what you just experienced-in this story-really happen? Well, it has never happened to me, and probably not to you either, but it is possible according to chemists and some other experienced aromatherapists so it seems appropriate to discuss it and try to sort fact from fiction.

Photo-toxicity is a very complicated, and too little understood topic, and there is more than just a little bit of disagreement on some of the basics such as exactly which oils are toxic, exactly how toxic they are, and how likely you are to have a problem with them. This article will contain the best information that I know of, mentioning the differing points of view and encouraging you to do a bit of study on your own, and maybe even encourage you to do a bit of very cautious experimenting in order to form your own educated opinion. While harm being done by an essential oil applied to the body is relatively rare, even one instance is one too many. Please don’t let that one instance be you, because of curiosity. (I say that because it is something I would be likely to do myself!)

Photo-toxicity-defined

The definition of photo-toxicity, as it applies to essential oils, is the amplification of ultraviolet light’s effect on skin following the application of certain essential oils to the skin before exposure to the sunlight or other sources of ultraviolet light. These effects are the result of a chemical reaction in the body between certain constituents in the oil and UV (ultraviolet light) rays. The effects on the skin may range from mild sunburn to sunburn with more permanent discoloration.  They may, if enough oil was used, and the exposure to sunlight was long enough, include damage severe enough to extend to deeper layers of skin.  Causing permanent destruction.  At least, this is what the literature claims.

Essential oils are not the only things that cause photo-sensitivity. There are drugs that do this too. Unlike essential oils where the oil must be applied to the skin to have a chance of causing a problem, ingesting the drug creates photo sensitivity of the skin as a side effect. Also unlike essential oils, one rarely hears about the photo-toxic effects of drugs.

According to e-medicine.com and other sites, one such drug is tetracycline. The list of photo-toxic drugs includes more that 20 separate drugs and drug categories. Others that are listed on e.medicine.com include ibuprofen, the salicylates, oral contraceptives, diuretics, non-steroidal anti-inflammatories, and—being un-involved with prescription medications and other drugs—a bunch of ones that I do not recognize and don’t have any idea why a person is prescribed them. If drugs and photo-toxicity applies to you, I hope you will do some research. Drug reactions are not the topic of this article, however, so back to photo-toxicity and essential oils.

A Little Bit of Chemistry

I do love chemistry, especially with the help of Dr. David Stewart and his marvelous book, The Chemistry of Essential Oils Made Simple. I have read it cover to cover several times and still learned something from it while preparing this article.

Furanoid Compounds and Photo-Toxicity

The compounds in essential oils that have nasty reputations for being photo-toxic are, most often, constituents called furanoids. Or more precisely, compounds that are subsets of furanoids called lactones and coumarins.

It is impossible to use the percentage of furanoids (even if you knew the names of all of them) in an essential oil to determine its degree of photo-toxicity because that percentage is irrelevant. The essential oil with the highest percentage of furanoids (at least 10 types of furanoid compounds) is myrrh . 20% to 27% of a typical batch of myrrh essential oil is furanoid compounds). Myrrh is not at all photo-toxic so long as it is not tampered with in a laboratory and much needed compounds taken out. In fact myrrh, as a complete oil, acts to protect the skin from the effects of ultraviolet light. Evidently there are other compounds in myrrh which, in the vernacular of Dr. Stewart, mitigate or “quench” the solar amplifying properties of the furans in myrrh. Perhaps quench is not the right word because, in myrrh, the furanoids seem to act is such a way as to help dissipate the UV energy. Dr. Stewart speculates that it is the sesquiterpenes in myrrh that make this difference. Continuing with the conundrums of furanoid containing essential oils is that fleabane, which has the next highest percentage of furanoids (who uses fleabane?) with 8% furanoids and peppermint with 5% are not photo-toxic oils either.

Belonging to particular plant family does not explain photo-toxicity either. For example, the essential oil distilled from the twigs and stems of Citrus auriantum (petitgrain essential oil) and the essential oil pressed from the fruit of this same species (bitter orange essential oil) are both photo-toxic but the essential oil made from the blossoms (neroli) is not photo-toxic at all and contains absolutely no furanoids. Petitgrain has only about 1% of furanoid compounds. This is enough for some reason, to render the oil problematic with sun exposure.

Part of the explanation, according to Dr. Stewart, lies in the configuration of the furanoid molecules. Furanoid molecules are built in ring formations. Those molecules with with 5-sided rings (furanocoumarins) are photo-toxic if there are no compounds in the essential oil to moderate this effect. Quoting Dr. Stewart, “the furan pentagon acts like a molecular prism, or magnifying glass, that favors the frequencies and wavelengths of ultra-violet (UV) light. . . and amplifies that portion of the spectrum.”

We mentioned above that sesquiterpene compounds may alleviate the effects of the furanoids in some essential oils. My speculation-and it is my own-is that if a blend contains oils known to be photo-toxic and also has oils high in sesquiterpenes, the photo-toxic essential oils will behave better than when they are standing alone as a single essential oil. All I know for sure is that I love to add sesquiterpene oils to the blends I have created, and that I have never experienced a photo-toxic reaction from these blends. I also wonder if there are other compounds that moderate the photo-toxicity of furanoids.

Using Photo-toxic Essential Oils Safely

Photo-toxic essential oils pose no problem at all unless you apply them to an area of your skin and then expose that area of skin to UV (ultraviolet) rays. Inhaling the aroma of the oil, putting it on some covered part of your body, or even taking it internally (I don’t recommend doing that) does not cause your skin to become photosensitive.

How long after you have applied an essential oil reputed to be photo-toxic to your skin must you avoid sunlight?

Now there is a difficult question. The range of opinions among the experts is quite astonishing! Most authorities recommend waiting a minimum of 12 hours before exposure to either sunlight or a tanning bed. Applying these sorts of oils at night should give you a safe margin. With bergamot, on the other hand, it is usually advised to avoid sunlight for up to 72 hours unless the skin where the essential oil was applied is protected from sunlight by being covered up very well by clothing. I would recommend something more than light cotton.

Please do not make the mistake of thinking that the longer it has been since you rubbed the oil on-say 6 or 7 hours-the less photo-toxic the oil will be. Experiments with bergamot have shown that a person’s photo-toxic response can actually be greater an hour or two after applying the oil than it would have been immediately. Two to four hours after applying the oil to your skin seems to be, with the majority of photo-toxic essential oils, the most critical period.  You cannot tell how bad the burns will be later by observing your skin while out in the sun. Photo-toxicity is a chemical reaction and chemical reactions may take a little time. The burns and destruction to your skin may not even show up until several hours after you have gone into the sun and then gone back home again.

This was a very intriguing (and alarming) piece of information to me. A few years ago (as some of you have heard me explain) I tried my own experiment with photo-toxic essential oils in a tanning bed. Once a week I would go to a tanning bed, stripe my abdomen with various essential oil (A to Z, except bergamot) and lay out for 20 to 30 minutes. I got a variously striped abdomen. Some stripes very light and some stripes a little bit red.  I experienced no burns of any kind. To me  this to meant that the photo-toxicity of essential oils was highly over-stated. I have expressed this opinion on many occasions. While over-exaggeration of the dangers may be present, I am counting my blessings that I waited until I got there to apply the oils. Perhaps not putting them on and then getting side-tracked for a length of time before UV exposure saved me some nasty discomfort and damage! Who knows? But with further study and the experience of others to go by, I will be a bit (only a bit) more careful in the future than I have been in the past.

Safety Elements

Attempting to wash an essential oil off your skin before exposure to sunlight, is completely ineffective as a protective measure. Most essential oils absorb so readily into the skin that they are completely out of reach by soap and water within moments, maybe even seconds, after you apply them. Any chemical reaction that would have been set up by the oil if you had not attempted to wash it off will still occur.

People with fair skins are far more likely to experience a photo-toxic reaction than are those with darker shades of skin. Very dark skin can tolerate up to seven times more oil with furanocoumarins before running into trouble than can the skin of fair-skinned Caucasian people. An already established suntan is some protection but I wouldn’t advise counting on it. (I was already pretty tan when I tried my tanning bed experiment and maybe that helped a little bit, too.)

Blends which contain photo-toxic essential oils will also be photo-toxic, as far as is known at this time. Do not make the mistake of thinking that having only a small percentage of a toxic oil will be a guaranteed protection. Remember bergamot which has only 1% of furanoids in it at all is considered to be the most photo-toxic of essential oils. If more than one of the essential oils in your blend includes 5-sided furanoid compounds, the overall percentage will be higher, perhaps high enough to exceed safety limits. Blends may be safer because of some of the other ingredients in there. But even chemists cannot guarantee which oils those are with any certainty.

The dilution of photo-toxic essential oils with carrier oils and thinking that will make them safer in the sunlight. Dr. Stewart, a chemist, claims that dilution of the essential oil does NOT provide any type of protection. Robert Tisserand and Dr. Gary Young, on the other hand, claim that dilution DOES help and helps a lot. They recommend using no more than four (4) drops total of any photo-toxic essential oil diluted in 30 ml (this is one ounce or 6 teaspoons) of a carrier oil to achieve safety. You will have to make up your own mind about this, but please be careful. My advice is to err on the side of caution and if you want to experiment, do so with very short exposure times.

How Do I know What Oils are Photo-Toxic?

Knowing which essential oils are photo-toxic, and which blends these essential oils are in, will help you to be cautious and safe. Putting your essential oils only on areas of skin that you do not expose to sunlight. Places such as your feet, or perhaps your chest and back—unless you know what is in the oils and whether or not it is photo-toxic, is really the only safe way to apply essential oils if you are going to be out in the sunlight.

Essential Oils that are Considered to be Photo-toxic

The problem with making a list of photo-toxic essential oils is that various authorities are not in agreement on what oils belong on the list. Everyone agrees that bergamot is by far the most photo-toxic of the essential oils. Everyone seems to understand that some of the citrus essential oils are photo-toxic.

Oils on Everybody’s Lists:

Bergamot
Bitter Orange
Grapefruit (less so)
Lemon (pressed)
Lime (pressed)
Petitgrain

Additions from Dr. Stewart:

Angelica
Rue

Possibly (according to others):

fennel
anise
cumin

Additional Oils from Other Lists: (perhaps less reliable lists)

Ginger
Tangerine

Butterfly blends with 1 or more of the oils that are on everybody’s lists as an ingredient:

^LeAcknowledge, ^LeBaby Me, ^LeBeloved, ^LeBountiful, ^LeDreams, ^LeEndoRelief, ^LeEverlasting,  ^LeFaith, ^LeHeart Song, ^LeIntention, ^LeLiteN, ^LeMyGraine, ^LePurify (only grapefruit), ^LeSego Lily (only grapefruit), ^LeSunburst (grapefruit and lemon), ^LeTomorrow, ^LeTurmoil, ^LeUnity, ^LeWakeup (grapefruit), ^LeWeightless

Lemon, in a small percentage, is an ingredient in 16 additional blends. It has never caused a problem for anyone that I have heard about. As mentioned at the beginning of this article, in all of these years, I have never seen a problem with any of the blends listed above. Also, my favorite place to put essential oils (and to advise others to put them) is on the feet or in the tub. You would think I would have experienced a problem from “tubbing” since I always add essential oils to my bath. I would expect a problem with walking about in sandals which I often do, or with tanning beds since I almost always have essential oils on my feet.

Final Advice

My advice, in the face of this frightful information, is to put your oils on your body in places where the sun won’t shine. If you want oils on your face and arms be careful to use a product that is not on anyone’s list. Or to cover that area of skin if you are going out into the sun. Remember that blends, because of the other oils in them, may be less likely to be photo-toxic. Or they may be more photo-toxic because there is more than one listed oil in them.

Please don’t let this article make you paranoid or convince you that essential oils are not safe. I have been putting essential oils on my body for many years. This has NEVER been a problem for me using Butterfly oils. (I’ve said this before.) I have not paid any attention to whether the essential oil I want to put in a blend is considered photo-toxic. Except for bergamot, I have not worried about it, not even with children. I don’t get out into the sun as much as I should. When I do it is usually a lot of sun, and I use my essential oils as usual. My husband and sons spend a lot of time in the sun as well. Here again, photo-toxicity has never been a problem.

I hope this article is helpful, BUT doesn’t cause you to do less good with these amazing healing oils than you would before this article was written!